Upgrade question

[mo0p]

Hello,

Have a question regarding upgrade process.

In short.. i screwed myself during my first build.. and now i am paying the price :)

I currently have a RAIDZ1 of 3x 3tb disks, and it is about 81% full, i am now getting alerts / warnings about capacity. After reviewing my options i would like some input from the community on how to proceed and get some tips / advice.

option 1) replace each disk one at a time with larger (4 or 5 TB disks) .. this scares the hell out of me, as during the re silvering process .. i am opening my self up to a RAID0 like issues where any one disk failure during resilver means total loss of data.. :p

option 2) purchase 4 new disks and build a raidz2 config, and move everything over from raidz1 array.. this will cost me cash for new PSU that has enough sata power connectors .. and a HDD bay for the 5.25" bays in the front of the pc case to accommodate the extra disk that i do not have room for in the pc case..

option 3) purchase 3x 3tb disks and build new vdev and add to existing zpool .. however i will be setting myself up for failure again when 1 disk dies and during re silver process i will have high chance of failure ..

Question is.. I dont hear too many horror stories of people resilvering raidz1 resulting in total loss of data,..but even the though spooks me.. I understand option 2 is the best as i am resolving an issue of using raidz1 .. however it will cost me the most $$$.. Are there any other options or have i missunderstood my above options in anyway?? any help / input / ideas is MUCH appreciated.. thanks!!

Specs:
Build - 9.2.1.5
CPU-i3-2120
Mem- 16GB corsair xms2
Nic - Intel 4 port Pro/1000 (3 port LACP link with vlan for iSCSI traffic, 1 mgmt interface)
Disk:
3x 3tb WD Red - Media CIFS share
3x 500GB WD red - iSCSI for ESXi host
60gb ssd FreeNAS OS

 

[mjws00]

If I was in your shoes looking to spend the least amount and end up with a better config. I'd buy 3 3TB drives which are often the current sweet spot for $/GB. I'd rebuild the pool with 6 disks in z2. Restore my data to the new pool. This puts you onto an optimal z2 vdev with lots of space. You may not have a back up or working space in which to do that. An extra drive might mitigate that? Or some clever shuffling between workstations etc.

I tend to look at the value of media pools in terms of time it would take to re-rip or replace. Personally I have no use at all for z1 raid, there is an unknown risk there but it is real. Tons and tons of media collections run on non-redundant storage with no backups. The logic being simply that the collection can be rebuilt, even if extremely painful. Someone with 3000 cd's ripped to FLAC or 1000's of blu-rays to huge mkv's will have a different viewpoint. That one will always be personal choice.

I would shy away from resilvering to larger disks. Feels like choosing Russian roulette on z1. Blech.

I think you have a pretty decent understanding of your options. I'd really try and land on a pool design that is safe and excellent if you possibly can. Going halfway isn't much better than just ignoring fault tolerance all together. Good luck.

 

[cyberjock]

Question is.. I dont hear too many horror stories of people resilvering raidz1 resulting in total loss of data,..but even the though spooks me.. I understand option 2 is the best as i am resolving an issue of using raidz1 .. however it will cost me the most $$$.. Are there any other options or have i missunderstood my above options in anyway?? any help / input / ideas is MUCH appreciated.. thanks!!

Wha!? You realize that the anti-RAIDZ1 bandwagon is *because* we've had users lose their data with RAIDZ1s? We see it weekly, if not more frequently.

Edit: Option 2 that you gave is the best of the three, but I do like @mjws00 and his option. 6 disk RAIDZ2 would work very well for you. ;)

 

[danb35]

A variation of option 2: Buy 5 disks. Set up four of them as a new pool in a RAIDZ2 configuration, and move your data over (however you want; ZFS replication is probably the best bet). Then destroy your current pool, and extend the new pool with four disks (your current three plus the remaining new one) in another RAIDZ2. Adds one disk's worth of cost to your option 2, but doubles your storage space, and doesn't require you find space to back up 5 TB of data while you're mucking about with the array.

 

[mjws00]

Pretty sexy transition, danb35. He does end up with 4 disks parity out of eight like that. Same space as 6 disk z2 but no transfer hassles.

Some good options presented, op. Enjoy your new space.

 

[danb35]

If he does my suggestion right*, he won't even need to reconfigure jails or anything. But, as you say, it uses 4 disks for parity. That, of course, also means he can lose up to four disks, as long as they're the "right" four disks (i.e., no more than two from each vdev). Pros and cons. More disks for the same amount of storage, but greater redundancy, and less data storage hassle.

* "right", above, means this:

• Create newpool on new disks.
• Replicate, or otherwise transfer, data from oldpool to newpool
• Destroy oldpool
• Extend newpool with four disks (old 3 plus remaining 1 new)
• Detach (export) newpool, but DO NOT mark disks as new
• From CLI, do:
  • zpool import newpool oldpool # This will rename newpool to oldpool
  • zpool export oldpool
• From Web GUI, auto-import pool